Fluid-brake.



r der.

'surfaces to 'become worn to WALTER HEILEMANN,

OF ESSEN-ON-THE-RUHB, GERMANY, ASSIGNOR TO FRIED.

KRUPP AKTIENGESELLSCHAFT, OF ESSEN-ON-THE-RUHR, GERMANY.

FLUID-BBAKE.

Specification of Letters Patent.

Pateted Dec. 28, 1909.

Application filed April 21, 1909. Seria] No. 491351.

this type of brake is effected, for example,

by having projections on the rotatable part engage in curved guide-grooves in the brakecylinder 'proper or in a guide-rod Secured centrally in the brake-cylinder, the projections sliding along the walls of the guidegrooves during the relative longitudinal movement of the pisten and the brakecylin- The fiuid-pressure created during the piston-part braking will cause the rotatable against to become pressed with great force its resisting hearing on the pisten or the piston-rod, the pressure acting throughout the entire braking path. Even if no other surfaces of the rotatable piston-part are exposed to the action of the fluid the pressure of the fluid will at least act on the projections of the rotatable piston-part which engage in the guide-grooves. Due to this fact considerable friction is produced between the Contacting surfaces of the rotatable pis- `ton-part and its resisting hearing. This frietion will, among other things, have the effect of causing the rotatable pisten-part to ofler considerable resistance to being turned by the projections which slide in the guidegrooves. The projections of the rotatablq piston part will therefore equally be presscd with considerable force against the appurtenant walls of the guide-grooves so that considerable friction is also produced between these parts of the fluid-brake. As the contacting surfaces' of these parts must be comparatively small because the guide-grooves generally have small depth, the friction between these parts may cause the Contacting such an exteut that intermediate spaces are produced between the projeetions of the rotatable piston-part and their guide-grooves. termediate spaces remain open throughout the entire brakng-path and they increase in These in-,

an undesirable manner the passages proper for the control of the flow of the fluid. In

'case of great wear these intermediate spaces may have the efiect that the forces effecting the recol and counter-recoil do not any .longer become entirely absorbed, so that a Shock takes place at the end of the recoil or the counter-recoil. If, for structural reasons, the projections of the rotatable pistonpart must be very narrow the frietion between the rotatable piston-part and the piston may even cause complete destruetion of the projections.

The object of the present invention is to remove, chiefly for the recoil, the drawbacks pomted out in the foregoing. This object is obtained by providing a hollow space between the rotatable piston-part and that sur.- face which serves as resisting hearing for the rotatable piston-part during recoil. This hollow space is adapted to receive brakefluid and it communicates with that side of the brake-cylinder from which brake-fluid is forced out during recoil.

In the accompanying drawing, the inventon is, by way of example, shown applied to the type of fluid-brake shown in the patent of Otto Lauber and Norbert Koch, #881045, of May 5, 1908.

F igure l is a longitudinal section through the pisten and a part 'of the b'ake-cylinder, and F ig. 2 s a Section 'on line *2-2, Fig. 1, looking from the left.

indicates the brake-cylinder in which spral grooves a are cut. The piston-rod B termmates in a head I which is provided with an axial bore 6 extending to the front face of the head. The free end of the head s provided with a flange If. The head IP is provided with an annular piston-body C which is screwed on the head on the side toward the piston-rod. A ring D which is provided with projections CZ snugly fitting n the guide-grooves a is rotatably mounted on the head 6 The fluid'passes from one side of the piston to the other through the grooves ar, of the brake-cylinder and passages 0 in the piston-body C and in the head b which passages open into the bore b An annular space (1 (Fig. l) which is formed by a rccess in the rin D is provided between the flange I) an the ring D and is adapted to receve brake-fluid. Through the' medium of channels d (see also Fig. 2)

i communicatcs with that side of the brake- "cylinder--the piston rod side--from which `When "the brake-fluid is forced out during the recoil. iston recoils after firing, inthc direction of the arrow a: (Fi 1), the projections d slide alongthe wal s of the spiral ooves a and turn the ring D relatively to e piston The fluid-pressure, which by` reason of the movement of the pisten is T created on the piston-rod side of the brakecylinder A, acts onthe projections (Z of the ring ,D extending into the grooves (1 and forces the ring against that 'surface of the brake-fluid at 'the same time exerts a pres-- flange b which serves as resisting hearing for the ring; Through the medium of the channels d and the hollow space (l the sure 'on the ring 'D which counteracts the fluid-pressure acting on `the. projections (l 'of the ring. The ring D is therefore relieved of :pressure and the friction between the ring; and the flange. b is'thus efi'ectiveb decreased and the wear on the walls of the grooves a and on the projections (2 which cause thering D to rotate is consequently equally decreased. 4

Although the invention is primarily adapti ed for use for-.the recoil, as the forces acting during the recoil are considerably greater than; those acting during the counter-recoil, t is evdent that the invention is not limited .to=suchuse. On the contraryin the embodij recoil? t is preferable to make the fluid-f i space between the rotatable pisten-part and its resisting bearing of 'such dimensions that the ipressure which is exerted on the rotatable piston-part due to the provision of the aforesaidfluid-space is approxinately equal tothe pressure 'exerted by thebrake-fluid on :the projections d of the ring D.

Having'thus described the invention what is claimed and desired tobe Secured by Letters Patent, is:-

1. In a'recoil-gun fiuid-brake piston, having apart ,which rotates relatively to the pston and issubjected to the braking pressure a fluid pressure counter-balance acting n ponsad relatvely rotatng` part 111 oppov stion to the braking ressure.

2 Ina `fluid-brake or recoil-guns, a brake cyl nder,` iston working in said brake cylnder'` an having a part which rotates relatvely to the rpiston and is subjected to s braking fluid pressure means supplying fluid iunderrpressure to the side of said relatively 'otating part opposite to that which cncounters tle-brakng pressure.

:3. .X fluid-hrake having a brake-cylinder, a pisten provided with a part. engagmg a part of the brake-cylinder and rotatable relatively to the piston, a surface formng. a rcsisting hearing for said pisten-part dur-` ing the movement of the pisten, a hollow space located on one side of the rotatable pisten-part. between said surface and the rotatable pisten-part, and a passage p'o-` i viding communication between said hollow space and ,the space of the brake-cylinder on the other side of the rotatable pistenpart.

i 4. A fluid-brake having a brake-cylimler, a pisten provided with a part engaging a part of the b'ake-'cylinder and rotata'ble:

relatively to the piston,-.-a surface forniug a resisting hearing for said pisten-part during recoil, a hollow space adapted to receive b'ake-fluid and located` between said surface and the rotatable pisten-part, and neans providing communication between said hollow space and that. space of ?the h'ake-cylinder from which the brake-fluid is forced out during recoil.

A fluid-brake having a b'ake-cylide', I

a pisten provided with a part engaginga e part of the brake-cylinder and' 'otatable reltively to the pisten, a surface forning a a resisting hearing for' said pisten-part during counter-recoil, a hollow spacemdapted to receive breke-fluid and located between' said surface and the rotatable pisten-part, and'means providing communication between said hollow space and that space of the brake-cylinder from which the brakefluid is forced out during counter-recoil.`

G. A fiuid-brake having a hrake-cylinder, a pisten provided with a part engaging a `.art of the brake-cylinder and rotatable rclatively tothe piston', said pis-ton .part. having a surface exposed to the action of the fluid-'pressure during the movement of the; pisten, a surface forning a resisting bearing for said piston-part during the-movement of the piston,`a'hollow space located on one side of the piston-part between `said bearing'surface and the piston-part, and :a passage providing communication between said hollow space and the space of the brakecylinder on the other side of the rotatable piston-part, said hollow space being of such 'dimensione that the pressu'e of the brake- 

